Main Drain was an energy draining robot monster used by the Machine Empire, and later by King Aradon. In battle, he shot his drain tubes underground and attached them to the Zeo Megazord, intending to drain its power supply and feed himself with it. He was the first monster to ever break a Megazord saber, which broke in two after Main Drain electrocuted the Zeo Megazord. He then broke into the Power Chamber and used his drain tubes to sap Alpha 5 of his life force, nearly succeeding until Somnibot stops him. He was destroyed by the Red Battlezord.